Earlier this week, we reported that a Mozilla Fellow had conducted research into the widespread manner in which mobile tracking is performed. Now, another Mozilla Fellow, Hang Do Thi Duc, has created Data Selfie to tell you more about you based on your Facebook activity; essentially you can find out much of what Facebook knows about you, but won’t tell you it knows.

Discussing how the add-on works, Hang said:

“Every time you like, click, read, or post something on Facebook, Facebook knows. Even if you don’t ever comment of share much, Facebook learns about you as you scroll through your feed.

My add-on does something similar. It’s here to help you understand how your actions online can be tracked. It does this by collecting the same information you provide to Facebook, while still respecting your privacy.”

In terms of the data that’s collected, from the extension’s dashboard you’ll see:

The last time you were online

Your total Facebook usage time

An activity timeline to let you know more about the interactions you've had

Your top friends based on the amount of time you've spent reading their posts

Your top pages based on the amount of time you've spent reading their posts

Likes for posts, photos, or videos

Aspects of your personality, health and activity levels, shopping preferences, as well as religious and political beliefs

Up until now, the only way to really find out what Facebook has on you was by demanding your information of discs which you’d be able to trawl through, but with this extension you get a much more detailed and precise look at your data, and obtain real insight into what Facebook probably knows about you. In order to extract things such as orientations and keywords, the add-on uses IBM’s Watson for natural language processing, and a machine learning API from the University of Cambridge. Importantly, data collected by the add-on is only stored locally and not in the cloud.

This very intriguing add-on can be downloaded for both Chrome and Firefox and you can learn more at the Data Selfie website.